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Perry–Robertson Formula
The Perry–Robertson formula is a mathematical formula which is able to produce a good approximation of buckling loads in long slender columns or struts, and is the basis for the buckling formulation adopted in EN 1993. The formula in question can be expressed in the following form: \sigma_m = \frac \left(f_y +\sigma_e\left(1+\theta\right) - \sqrt \right) with \theta = \frac where: * \sigma_m is the average longitudinal stress in the beam's cross section * f_y is the material's elastic limit * \sigma_e is the average tension measured in the cross section which correspond to the beam's Euler load * w_ the amplitude of the initial geometrical imperfection * c distance from the cross section's centroid to the section's most stressed fiber * i the section's radius of gyration The radius of gyration or gyradius of a body about the axis of rotation is defined as the radial distance to a point which would have a moment of inertia the same as the body's actual distribution of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buckling
In structural engineering, buckling is the sudden change in shape (Deformation (engineering), deformation) of a structural component under Structural load, load, such as the bowing of a column under Compression (physics), compression or the wrinkling of a plate under Shearing (physics), shear. If a structure is subjected to a gradually increasing load, when the load reaches a critical level, a member may suddenly change shape and the structure and component is said to have ''buckled''. Euler's critical load and Johnson's parabolic formula are used to determine the buckling stress of a column. Buckling may occur even though the Stress (mechanics), stresses that develop in the structure are well below those needed to cause Catastrophic failure, failure in the material of which the structure is composed. Further loading may cause significant and somewhat unpredictable deformations, possibly leading to complete loss of the member's load-carrying capacity. However, if the deformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columns
A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. The term ''column'' applies especially to a large round support (the shaft of the column) with a capital and a base or pedestal, which is made of stone, or appearing to be so. A small wooden or metal support is typically called a '' post''. Supports with a rectangular or other non-round section are usually called '' piers''. For the purpose of wind or earthquake engineering, columns may be designed to resist lateral forces. Other compression members are often termed "columns" because of the similar stress conditions. Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest. In architecture, "column" refers to such a structural element that also has certain proportional and decorative fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strut
A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for strut, but some sources distinguish that struts are braces for holding compressive forces apart, while stays are braces for keeping stretching forces together. Human anatomy Part of the functionality of the clavicle is to serve as a strut between the scapula and sternum, resisting forces that would otherwise bring the upper limb close to the thorax. Keeping the upper limb away from the thorax is vital for its range of motion. Complete lack of clavicles may be seen in cleidocranial dysostosis, and the abnormal proximity of the shoulders to the median plane in cases of this genetic condition exemplifies the clavicle's importance as a strut. Architecture and construction Strut is a common name in timber framing for a support or brace of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EN 1993
EN or En or en may refer to: Businesses * Bouygues (stock symbol EN) * Island Rail Corridor, formerly known as the Esquimalt and Nanaimo Railway (reporting mark EN) * Euronews, a news television and internet channel Language and writing * N, 14th letter of the Roman alphabet * EN, a mark in Sumerian cuneiform script for a High priest or Priestess (meaning "lord", or "priest") *En (digraph) /‹en›/, a phoneme * En (Cyrillic), 15th letter of the Cyrillic alphabet *En (typography), a unit of typographical width ** Dash#En dash /en dash/, a dash of length 1 en * En language, a language spoken in northern Vietnam *English language (ISO language code: en) Organisations * Eastern National, a US organization providing educational products to National Park visitors * English Nature, a former UK government conservation agency * Envirolink Northwest, an environmental organization in England Religion * En (deity) in Albanian mythology Science and technology * Engineer * E''n'' (L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centroid
In mathematics and physics, the centroid, also known as geometric center or center of figure, of a plane figure or solid figure is the arithmetic mean position of all the points in the figure. The same definition extends to any object in n-dimensional Euclidean space. In geometry, one often assumes uniform mass density, in which case the '' barycenter'' or ''center of mass'' coincides with the centroid. Informally, it can be understood as the point at which a cutout of the shape (with uniformly distributed mass) could be perfectly balanced on the tip of a pin. In physics, if variations in gravity are considered, then a '' center of gravity'' can be defined as the weighted mean of all points weighted by their specific weight. In geography, the centroid of a radial projection of a region of the Earth's surface to sea level is the region's geographical center. History The term "centroid" was coined in 1814. It is used as a substitute for the older terms "center of grav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radius Of Gyration
The radius of gyration or gyradius of a body about the axis of rotation is defined as the radial distance to a point which would have a moment of inertia the same as the body's actual distribution of mass, if the total mass of the body were concentrated there. The radius of gyration has dimensions of distance or 0LT0and the SI unit is the metre (m). Formulation Mathematically the radius of gyration is the root mean square distance of the object's parts from either its center of mass or a given axis, depending on the relevant application. It is actually the perpendicular distance from point mass to the axis of rotation. One can represent a trajectory of a moving point as a body. Then radius of gyration can be used to characterize the typical distance travelled by this point. Suppose a body consists of n particles each of mass m. Let r_1, r_2, r_3, \dots , r_n be their perpendicular distances from the axis of rotation. Then, the moment of inertia I of the body about the axis of ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
